It may happen that the water temperature is high when showering, when the temperature is higher than the proper value of 45° C., people feel uncomfortable, hurt, even get scaled. It happens when cold water is not serviced well, when the pipe gets wrong or when cold water and hot water are not mixed well, these situations are unpredictable. How to cut off the water with high temperature sensitively in a short time is a necessary humanization demands; meanwhile, if the device is smart enough to integrate into kinds of small sanitary wares, it makes it a convenient one to benefit the manufacturing and the users.